I. Field
The present disclosure relates generally to communication, and more specifically to techniques for performing automatic gain control (AGC) for wireless communication.
II. Background
In a wireless communication system, a transmitter typically processes (e.g., encodes and modulates) data and generates a radio frequency (RF) modulated signal that is more suitable for transmission. The transmitter then transmits the RF modulated signal via a wireless channel to a receiver. The wireless channel distorts the transmitted signal with a channel response and further degrades the signal with noise and interference.
The receiver receives the transmitted signal, conditions the received signal to obtain a baseband signal, digitizes the baseband signal to obtain samples, and processes the samples to recover the data sent by the transmitter. The received signal level may vary over a wide range due to various channel propagation phenomena such as fading and shadowing. Hence, the receiver typically performs AGC to avoid saturation of various circuit blocks in the receiver. Saturation may occur when the input of a circuit block exceeds a maximum input signal level or the output of the circuit block exceeds a maximum output signal level. Saturation may result in distortion components that may degrade performance. Hence, it may be desirable to perform AGC in a manner to obtain good performance.